Imaging protocols with modern CT scanners and other imaging equipment now allow for high resolution exam images to be obtained for various parts of the body within short time intervals. The resolution on these routine examinations is now similar in quality to the protocols used for screening or diagnostic protocols used to find specific conditions. In addition, computer-aided detection (CAD) software helps radiologists read medical images such as mammograms and computed tomography (also known as CT or CAT scanning) chest scans.
One example is in the area of coronary artery calcium scoring. Modern scanners allow for evaluation of coronary arteries (calcium in the case of non contrast enhanced scans and the lumen in the case of enhanced scans), even when conducting only a routine CT chest scan. Previously, a specific protocol was required for evaluation of the coronary arteries. Thus, the coronary arteries may now be visualized in a routine chest protocol, such as a CT chest scan obtained to evaluate a lung disease such as pneumonia, with nearly the same quality as in a scan specifically run for finding cardiac related conditions.
With respect to CAD software, computer-aided detection may be used by medical professionals such as radiologists to re-evaluate medical images for a given condition. Typically, a radiologist will review images from a CT scan and then activate CAD software, which marks potential abnormalities for a subsequent review by the radiologist. One example of software useful for a CAD system is disclosed in U.S. Pat. No. 6,766,043 to Zeng, et al., issued Jul. 20, 2004 and entitled “Pleural Nodule Detection from CT Thoracic Images,” which is incorporated by reference. Zeng discloses an algorithm that recovers regions of possible pleural nodules left out of an organ field or otherwise undetected due to the nature of low level image processing in the organ field.
Unfortunately, such known methods do not provide an accurate way to detect secondary conditions that may present in a medical image initially acquired for another condition, other than the condition that is the subject of the initial scan. Until now, no systems compensated for the differences in accuracy between an imaging technique directed to a first condition, and a more specific imaging technique directed to testing for a second condition. In contrast, the present invention takes advantage of recent improved image scanning quality to provide, for the first time, a procedure for managing patient care for such secondary conditions while compensating for the differences in accuracy between imaging techniques used for differing tests.